Shahrzad Shokoofi - Patient Safety Research Center, Clinical Research Institute, Urmia University of Medical Sciences, Urmia, Iran.
Ayda Esmaeili - Experimental and Applied Pharmaceutical Sciences Research Center, Urmia University of Medical Sciences, Urmia, Iran.
Ali Yekanlou - Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran.

Coagulopathy as a reversible dose-dependent side effect of rifampin is rarely observed in patient on rifampin in associate to inducing vitamin K deficiency. We reported a middle-aged man on a brucellosis three-drug regimen (including rifampin) who was admitted to the hospital due to a rheumatoid arthritis flare-up with increased partial thrombin time and international normalized ratio. Abnormal coagulation tests were discovered as an unintentional finding in the absence of clinical signs of bleeding. However, the coagulation tests returned to normal in ۴۸ hours by withdrawing rifampin and administering ۲.۵ mg of oral vitamin K. The patient was discharged with a new brucellosis regimen including doxycycline and trimethoprim/sulfamethoxazole.

Rifampin, Coagulopathy, vitamin K, adverse drug reaction, case report